The Principle Against Unjustified Enrichment

Abstract

Abstract A celebrated abstraction is the maxim from the Digest that no one should be enriched at another’ s expense. The late scholastics and then the northern natural lawyers thought that this principle could explain the law of unust enrichment. Since the 19th century, German jurists, in particular, have been trying to bring it down to earth. Windscheid and his contemporaries agreed that this principle is too broad, a ‘ false abstraction’, ‘ untrue at this level of generality’.2 3 The truth was suggested by another Roman maxim which said a person was liable for ‘ a thing which he has without a just basis (justa causa)’ D According to Windscheid, a person enriched at another’ s expense ‘ has the duty to justify (herauszugeben) to the disadvantaged party, why he has become richer’.4 That conclusion is expressed by the general principle of § 812(1) of the German Civil Code: one who has received something through another’ s performance or at his expense in some other way without legal basis (ohne rechtlichen Grund) is obligated to give it back’. Yet 20th century German jurists have found that statement too broad as well. In 1934, Walter Wilburg claimed that it was impossible to formulate any general rule as to when enrichment is unjustified. Ernst von Caemmerer agreed. It is not true that an enrichment is unjustified when the person enriched has no contractual or statutory claim to be. A person might lose his rights to another by prescription. Or he might renounce a right which is consequently acquired by someone else.